Block Diagram Research Articles

Intelligent fuzzy back-stepping observer design based induction motor robust nonlinear sensorless control

Introduction. The control algorithm of Induction Motor (IM) is massively dependent on its parameters; so, any variation in these parameters (especially in rotor resistance) gives unavoidably error propagates. To avoid this problem, researches give more than solution, they have proposed Variable Structure Control (VSC), adaptive observers such as Model Reference Adaptive System, Extended Luenberger Observer (ELO) and the Extended Kalman Filter (EKF), these solutions reduce the estimated errors in flux and speed. As novelty in this paper, the model speed observer uses the estimated currents and voltages as state variables; we develop this one by an error feedback corrector. The Indirect Rotor Field Oriented Control (IRFOC) uses the correct observed value of speed; in our research, we improve the observer’s labour by using back-stepping Sliding Mode (SM) control. Purpose. To generate the pulse-width modulation inverter pulses which reduce the error due of parameters variations in very fast way. Methods. We develop for reach this goal an exploration of two different linear observers used for a high performance VSC IM drive that is robust against speed and load torque variations. Firstly, we present a three levels inverter chosen to supply the IM; we present its modelling and method of control, ending by an experiment platform to show its output signal. A block diagram of IRFOC was presented; we analyse with mathematic equations the deferent stages of modelling, showed clearly the decoupling theory and the sensorless technique of control. The study described two kinds of observers, ELO and EKF, to estimate IM speed and torque. By the next of that, we optimize the step response using the fuzzy logic, which helps the system to generate the PI controller gains. Both of the two observers are forward by SM current controller, the convergence of SM-ELO and SM-EKF structures is guaranteed by minimizing the error between actual and observed currents to zero. Results. Several results are given to show the effectiveness of proposed schemes.

Estimation of an Extent of Sinusoidal Voltage Waveform Distortion Using Parametric and Nonparametric Multiple-Hypothesis Sequential Testing in Devices for Automatic Control of Power Quality Indices

Deviations of power quality indices (PQI) from standard values in power supply systems of industrial consumers lead to defective products, complete shutdown of production processes, and significant damage. At the same time, the PQI requirements vary depending on the industrial consumer, which is due to different kinds, types, and composition of essential electrical loads. To ensure their reliable operation, it is crucial to introduce automatic PQI control devices, which evaluate the extent of distortion of the sinusoidal voltage waveform of a three-phase system. This allows the power dispatchers of grid companies and industrial enterprises to quickly make decisions on the measures to be taken in external and internal power supply networks to ensure that the PQI values are within the acceptable range. This paper proposes the use of an integrated indicator to assess the extent of distortion of the sinusoidal voltage waveform in a three-phase system. This indicator is based on the use of the magnitude of the ratio of complex amplitudes of the forward and reverse rotation of the space vector. In the study discussed, block diagrams of algorithms and flowcharts of automatic PQI control devices are developed, which implement parametric and nonparametric multiple-hypothesis sequential analysis using an integrated indicator. In this case, Palmer’s algorithm and the nearest neighbor method are used. The calculations demonstrate that the developed algorithms have high speed and high performance in detecting deviations of the electrical power quality.

Simulation of optoelectronic oscillator injection locking, pulling & spiking phenomena

Complex envelope and reduced phase simulation models describing the dynamical behaviour of an optoelectronic oscillator (OEO) under injection by an external source are described. The models build on the foundations of a previously reported delay integral/differential equation (DDE) theory of injection locking of time delay oscillators (TDO) such as the OEO. The DDE formulation is particularly amenable to high precision simulation using the Simulink™ block diagram environment. The correspondence between the blocks and the oscillator components offers intuition and considerable freedom to explore different circuit architectures and design variations with minimal coding effort. The simulations facilitate the study of the profound effect the multimode nature of a TDO has on its dynamical behavior. The reduced phase models that make use of the Leeson approximation are generally successful in reproducing the results of complex envelope models for established oscillations except for spiking phenomena for which the Leeson approximation fails. Simulation results demonstrating phenomena not captured by classical injection theory are presented, including multimode oscillation, the appearance of sidemodes in the RF and phase noise spectrum, and persistent spike trains redolent of recent experimental observations of 2π\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$2\\pi $$\\end{document} phase pulse trains in a broadband OEO under injection.

Development of software for contactless control of UAVs

The article is devoted to the development of a program for contactless control of a UAV using a neural network that tracks the position of an object. For these purposes, a corresponding model was trained on the ultralytics YOLOv8 neural network. The graphs of the training of this model are presented, demonstrating the change in the magnitude of the loss function over the bounding box and class, as well as the values of the mAP50-95 metric. The training was completed when the value of the mAP50-95 metric was 0.855. Software has been developed to control the UAV using hand movements, its block diagram and description are given. The program reads the coordinates of the hand in each frame, calculates its area, evaluates the received data and sends control commands to the copter, which moves in the appropriate direction for a given step, including a certain group of LEDs. At the same time, the screen displays a simulation of the drone›s movement in two projections (front and top) and displays the relative coordinates of the drone. The software was tested on a Geoscan pioneer mini quadcopter. It can be used for educational, demonstration purposes, in agriculture, UAV sports competitions, aerial photography and video filming and other fields of activity.

Method of parametric optimization of hydraulic structures for subzero temperatures

A method for optimizing design and geometric parameters using a "simplified" simulation of the water-cooling process is presented. This method allows solving the issues of operational manufacturability in the aspect of creating energy- and resource-saving constructions of water storage tanks. In the study to determine the size of underground and above-ground parts of the water storage tank the criterion of heat loss minimization is accepted and the mathematical model of water heat exchange with the ground under the condition of its homogeneity and stationarity of the thermal regime is compiled. The relationship between the height and the radius of the underground part at the minimum value of the heat transfer coefficient from water to the ground through the metal wall is established. Using the heat balance equation, an analytical expression is found that determines the aboveground fluid temperature for any instant of time. On the basis of the theory of differential calculus the condition of minimality of the cooling rate of water, which gives up heat through the side walls to the environment and air space under the roof of the vessel, was revealed, which made possible to optimize the size of its above-ground part. The relationship of the radius and the total volume of the water holding capacity was determined for the average values of ambient temperature and wind speed recorded in the region of the research. The developed algorithm of the method of "simplified" modeling and its representation in the form of a block diagram can be implemented at digitalization of calculation-analytical procedures for selection of structural and geometrical parameters of the vessel according to the criterion of minimum heat losses. The functions of the radius and the height of the underground and above-ground parts of the vessel from the argument of its total volume are graphically illustrated.

Research on the integrated failure analysis method of safety and security of fieldbus transmitters

Fieldbus transmitters are commonly used in modern industrial productions, particularly in Safety Instrumented Systems (SIS). Safety and security are critical considerations in the design and operation of these transmitters. Previous research has tended to address safety issues and security issues separately, but with the increasing complexity of network technology, it is important to analyze them simultaneously. In this paper, a systematic framework for comprehensively analyzing random failures and cyber-attack failures is proposed. The framework adopts the FMEA-IMEA method, which combines Failure Modes and Effects Analysis (FMEA) and Intrusion Modes and Effects Analysis (IMEA), to analyze failure modes and effects of fieldbus transmitters. In addition, by extending Reliability Block Diagrams (RBD), the impact of random failures and cyber-attack failures on fieldbus transmitters is quantitatively determined. At the same time, calculation approach of the residual error rate (RER), Component counting method, and Monte Carlo are used to determine random failure rate and cyber-attack failure rate. Using fieldbus pressure transmitter and fieldbus temperature transmitter as examples, the results demonstrate that security issues can significantly impact the safety integrity level. In fact, the safety integrity level is reduced from SIL3 to SIL1 when cyber-attacks are considered. Compared to existing FMEA, the proposed approach offers a more comprehensive analysis of random failures and cyber-attack failures in fieldbus transmitters.

Bayesian network approach for reliability analysis of mining trucks

Having a safe and efficient system for mineral transportation is a top priority for all mining operations. Trucks are the most widely used material transportation systems that are applied in both surface and underground mines. Any truck failure disrupts the mineral transportation process and consequently decreases the overall output. Therefore, the reliability analysis of such equipment plays a critical role in increasing the efficiency and productivity of a mining operation. This paper proposes a novel method for analyzing the reliability of a fleet of mining trucks based on the Bayesian Network modeling. Considering the reliability block diagram, the fault tree of trucks was developed according to the logical relationship between the units. Then, a dynamic Bayesian network was constructed according to the conditional probability analysis. Moreover, the relative contributions of each truck’s component to the occurrence of the fleet failure were studied by using critical analysis. The results of this paper show that the successful operation of the fleet of trucks is most sensitive to truck no. 5, which has the highest reliability level in all time intervals. The reliability of the fleet of trucks reaches 0.881 at 20 h, and the fuel injection system of the truck’s engine is the main leading cause of the trucks failure. A proper preventive maintenance strategy should be paid more attention to improve the reliability and availability of the engine system.

Мемристивные биосенсоры: классификация и энергоинформационная модель

The potential of memristive biosensors as an effective and dynamic link between engineering and biology, providing direct and functional communication for extracting information about biological processes in the human body, is discussed. Memristors can be part of a processing chain and, in the future, combine signal conversion with subsequent processing, acting as intelligent sensors. An energy-informational memristor model describing this nonlinear physical and technical effect and a parametric block diagram for describing such nonlinearity are proposed. To obtain a model of the nonlinear physico-technical effect of a memristor within the framework of the energy-informational model of circuits, a special functional dependence in the “charge-pulse” plane was revealed. It is noted that the memristive effect is observed not only in electrical circuits, but is also described for mechanical, thermal, diffusion, and optical circuits, which are well represented in terms of an energy-informational circuit model. The presented model of the memristive effect will expand the knowledge base of the computer-aided design system by including passports of memristive physical and technical effects. A classification of biosensors based on memristive effects is proposed, which will make it possible to supplement the knowledge bases of the computer-aided design system with passports of memristive physical and technical effects in accordance with this classification and parametric structural schemes of memristive physical and technical effects. The systematization of knowledge based on the identification of the characteristics and features of biosensors, as well as the classification of various types of memristors, will automate the process of choosing the most appropriate type of memristor, taking into account the required characteristics and features of the biosensor, which will lead to an increase in the efficiency of synthesis of new designs of memristive biosensors.

Security in cloud computing: Methods for ensuring privacy and integration in modern applications

Cloud computing has become a necessary component for data storage and processing and is becoming more widespread. However, there are threats to the security and privacy of user data, which is why it is important to find out the most effective methods for ensuring data security in the cloud. The purpose of the study was to develop methods aimed at ensuring privacy and security in cloud environments and in modern applications. The method of analysis was used to review other publications on the topic, and the method of experiment was used for practical implementation. The main results of the study include the development of a security monitoring programme. It analyses event logs and determines the number of failed login attempts, which indicates the detection or absence of suspicious activity. Access to resources is checked, and the necessary information is displayed on the console. A comparison table of cloud platforms has been created, considering their advantages and disadvantages in the context of data security and privacy. It specifies the criteria for delivering services to the selected services. A block diagram of ways to provide security in cloud computing is developed, illustrating the relationship between various aspects of providing security in cloud systems. It contains parameters and strategies for encrypting data, protecting sensitive data, and countering attacks. Various aspects of security and methods of ensuring privacy in cloud computing are considered, namely authorisation, intrusion detection, regulatory requirements, integration with modern applications, monitoring and logging, user identification and authentication. The practical significance of the study lies in the creation of innovative ways to help improve security and privacy in cloud computing. They will allow cloud developers and administrators to effectively protect user data and ensure their privacy in modern applications

THE STAGES OF IMPLEMENTATION OF THE TEACHER'S DIGITAL COMPETENCESELF-ASSESSMENT TOOL IN THE CONTEXT OF PROFESSIONAL DEVELOPMENT

The article highlights the development and steps of implementing a tool for self-assessment of digital competence of a teacher based on the experience of domestic specialists in the period of 2020- 2023. An analysis of approaches to the development of a self-assessment tool in the international educational community is carried out. Approaches to compiling a survey questionnaire based on the Digital Competence Framework for Educators (DigComp 2.1) are substantiated. The stages of development of a self-assessment tool for the teacher's digital competence are presented: development, improvement, implementation. The procedure for conducting the survey over four years is described. A block diagram of the creation and implementation of a teacher's digital competence self-assessment tool is presented. The principles that contributed to obtaining reliable data during the self-assessment of a teacher's digital competence are substantiated and presented. It is proved that the self-assessment tool of the teacher's digital competence should contain elements of identifying the degree of readiness to use ICT by teachers and educational institutions, which contributes to the development of recommendations and finding solutions to overcome existing problems. The concept of the readiness of teachers to use the tools of the information and educational environment for the implementation of educational activities in quarantine conditions is defined. The main indicators obtained during the all-Ukrainian survey of teachers in the system of general secondary education were analyzed, and the dynamics of the development of digital competence of teachers were revealed. The main content of methodological recommendations for postgraduate education, developed on the basis of the approbation of the self-assessment tool, is presented. The scientific novelty of the presented research lies in the discovery of new approaches, the development of principles and forms of self-assessment of the teacher's digital competence in the conditions of restrictions caused by the long quarantine and wartime in the country. The conclusions regarding the further use of the teacher's digital competence self-assessment tool in the system of postgraduate pedagogical education are substantiated. Prospects for further research are outlined.

Multidimensional Multi-Connected Fuzzy Interval-Logic Controller

The key features and the principle of operation of a multidimensional fuzzy interval-logic controller with interconnected adjustable parameters developed by the authors are considered. The scheme of interpretation of continuous physical quantities by an equivalent set of terms and the basic version of the block diagram of the regulator are presented. The main elements of the logical output block are described, including the block of production rules, which includes a predefined database of values of control actions on control objects in the form of ordinal numbers of terms of output continuous quantities. The advantages and features of setting up the mutual connections between the input and output continuous values of the regulator are considered, which is expressed in determining the functional dependencies between them. The set of parameters possessed by the terms of input continuous quantities in relation to specific output continuous quantities of the regulator is described. The methods of defuzzification of the values of output continuous quantities within the boundaries of their terms are shown. The possibility of combining input and output continuous quantities into groups when setting up mutual connections between them is described. The mechanism of determining groups of interrelated continuous quantities is illustrated, the total number of which is determined by forming a matrix of relationships, according to the author’s scheme. The algorithm of sequential processing of the contents of the cells of the matrix of relationships, consisting of three steps, is considered. Expressions are given for calculating the basic parameters of a multidimensional fuzzy interval-logic controller with interrelated adjustable parameters. The results of a computational experiment to reduce the system of production rules of the regulator in determining the relationships between input and output continuous quantities are presented.

Control system for noise-resistant electronic speed controller of a brushless electric motor for an unmanned aerial vehicle

Objectives. The high demand for unmanned aircraft and their efficiency makes the production of their components a matter of relevance. One of these components is the speed controller of the brushless electric motor of the propeller motor group. At the current time, Russian industry, however, does not mass-produce them. In order to start production, control methods and algorithms for the hardware and software parts of devices of this type are needed. Criteria for selecting the main components also need to be formalized. The aim of this work is to develop a method for the software control of electric motors. This includes block diagrams and invariant algorithms and methods for the calculated selection of parameters of the main microcontroller of the electronic speed controller.Methods. Methods of algorithmization, expert assessments, linear computational processes and experimental studies were used.Results. The paper presents the theoretical basis for controlling the required motors. It proposes a block diagram of the implementation of the controller, and a technique for switching windings when controlling with a trapezoidal signal is proposed. Examples are given in the form of an oscillogram. Based on theoretical research, an invariant algorithmic apparatus was developed for building software for various types of microcontrollers. Block diagrams of all the main modules of the software are also presented. The main ones include: the event switching algorithm; and the main endless loop of the microcontroller. The requirements for microcontrollers to create the various types of speed controllers are formalized herein and presented in the form of a set of mathematical expressions. They enable the number of required peripheral devices and microcontroller ports to be calculated according to the requirements for the microcontroller, as well as the computing power of the core used.Conclusions. Experimental studies show the reliability of the theoretical research presented herein. The results obtained can be used to select the optimal element base and develop software for speed controllers of electric motors of the propellers of unmanned aircraft.

Dependability Evaluation of a Smart Poultry House: Addressing Availability Issues Through the Edge, Fog, and Cloud Computing

Internet of Things (IoT) applications equip rural producers with decision support tools and automated solutions that boost agribusiness productivity, quality, and profit. However, most poultry farmers still use conventional methods of operation in which human workers carry out all routines for monitoring and controlling their farms at the expense of greater productivity. One of these human activities is manual weighing, which can be replaced by non-intrusive methods such as computational vision applications that estimate live poultry's weight using video cameras. Since Internet of Things (IoT) devices may have low computing power limiting the ability to process the data locally, they can transfer it to a fog or cloud data center, where they are processed. This paper aims to conduct a dependability study of a poultry house automated with a computer vision-based system for estimating poultry weight considering hierarchical models (e.g., Markov chain, Reliability Block Diagram, and closed-form equation) to represent the whole system and obtain steady-state availability and annual downtime. In addition, our purpose is to consider and compare different architectural solutions, such as edge and fog computing-based solutions. The proposed solution verified that a cloud-based application with no redundancy has a downtime of 34.14% and 9.176% hours when considering a hot-standby redundancy strategy in the office node of a cloud solution.

Quantitative evaluation method of operation reliability of substation relay protection device based on improved neural network algorithm

With the increase in power demand and the increasing complexity of the power grid, the operation of relay protection devices in substations is often unreasonable. Therefore, a quantitative evaluation method of operation reliability of relay protection devices in substations based on an improved neural network algorithm is proposed. The time-varying probability of misoperation of relay protection in substation is calculated based on the improved neural network algorithm, identifying misoperation behavior of relay protection device, obtaining the optimal hyperplane decision function, selecting kernel function, and construct a quantitative evaluation function of operation reliability of relay protection device. In the evaluation process, two stages of the evaluation process are carried out, namely, reliability block diagram analysis, failure mode evaluation, and verification of relay protection device operation state, so as to complete the reliability quantitative evaluation. The experimental results show that this method can minimize the error of evaluation training and improve evaluation efficiency. At the same time, the error rate is small, which can be controlled within 0.5%.

Modeling of the removal of combustion products in the pipe of a low-rise building as a control object

The features of the formation and methods of preventing condensation in the chimney of an apartment low-rise building with an individual decentralized heat supply system are considered. A mathematical model of the technological process of removing flue gases from gas boilers in an apartment building through a collective chimney pipe as a multidimensional control object with distributed parameters, which is understood as a set of thermophysical processes occurring during the removal of combustion products. Numerical simulation of a collective chimney pipe is performed on the example of a three-storey apartment building with gas boilers installed in each apartment as a control object. A method of step-by-step experiments is proposed. At the first stage, the dependences of the distribution of the temperature field inside the chimney during non-stationary operation of boilers and changing ambient temperature are obtained. The phenomenon of condensate occurrence has been confirmed experimentally, and the most characteristic areas subject to its occurrence have been identified. During the second stage of research, it was found that it is most effective and economically feasible to prevent the formation of condensate by using a heating cable in the attic and chimney head sections. It is shown that the change of control actions has an effect on the temperature of adjacent sections of the chimney. The revealed non-stationarity is taken into account by inter-channel connections through the object in the block diagram. It is proved that, in relation to solving the problem of removing combustion products from the chimney, an object with distributed parameters can be represented by a model with concentrated parameters, for which the structure is synthesized and proper operators and operators of inter-channel connections are found in the form of transfer functions with variable parameters. The resulting model is problem-oriented to create a two-dimensional automatic temperature control system on the inner surface of the chimney in order to prevent the formation of condensate in the pipe.

Joint Authentication Public Network Cryptographic Key Distribution Protocol Based on Single Exposure Compressive Ghost Imaging

In the existing ghost-imaging-based cryptographic key distribution (GCKD) protocols, the cryptographic keys need to be encoded by using many modulated patterns, which undoubtedly incurs long measurement time and huge memory consumption. Given this, based on snapshot compressive ghost imaging, a public network cryptographic key distribution protocol is proposed, where the cryptographic keys and joint authentication information are encrypted into several color block diagrams to guarantee security. It transforms the previous single-pixel sequential multiple measurements into multi-pixel single exposure measurements, significantly reducing sampling time and memory storage. Both simulation and experimental results demonstrate the feasibility of this protocol and its ability to detect illegal attacks. Therefore, it takes GCKD a big step closer to practical applications.

A block diagram approach to characterize the kinematic and torque relationship of three-port transmission mechanism

ABSTRACT This paper presents a kinematic and dynamic modeling of a three-port transmission mechanism using the block diagram technique. By exploiting the simplicity of the block diagram technique, unlike the more complex conventional approaches, the three-port transmission mechanism is systematically characterized to obtain the velocity kinematics and torque relationship. This is achieved by establishing a feedback connection of the three-port transmission mechanism in block diagram form, and obtain the close-loop input/output relationship using techniques known in the control community, such as Mason’s rule. Two categories of the three-port transmission mechanism were investigated including, the 1D rotation type (planetary gear) and the 2D rotation type (differential). The kinematic and dynamic expressions of both categories were shown to be easily obtained, identifying the characteristic differences. The velocity kinematics, torque relationships, and power analysis were expressed to validate the proposed modeling. Further verification using MATLAB Simulink shows a good agreement of the analytical expressions and the proposed block diagram model. To demonstrate the effective use of the proposed approach, the block diagram technique is applied in the design analysis of a south-pointing chariot device.

Thermoelectric climate control systems for agro-industrial facilities with non-linear control of Peltier modules

A promising direction in solving the problem of energy saving at agribusiness facilities is the use of an integrated approach - the principle of trigeneration, in which thermal energy is generated based on the thermoelectric method, which involves the use of special modules from thermoelements based on the Peltier effect. On the basis of this method, a climate control system for agro-industrial complex objects has been developed, represented by a block diagram and an equivalent functional model. To assess its compliance with a certain quality of the control process during the transition of the system to a new operating mode, a comparative analysis of the use of linear and nonlinear control algorithms for thermoelectric modules was carried out. In this case, the nonlinearities were set by two saturation links corresponding to the Saturation blocks in the MatLAB Simulink environment. With the help of the developed models, a study was made of the operation of the proposed climate control system in the time domain for the studied control modes of thermoelectric modules at different values of saturation blocks, according to the results of which it was found that the use of nonlinear control can reduce the time of transients, dynamic control error and oscillation, which unattainable using traditional linear algorithms.

Impact of various factors on the cutting performance of knives when processing food products

Determining the optimal geometric and kinematic characteristics of the working components is crucial for ensuring the quality performance of machines used in the cutting of semi-finished macaroni products. These characteristics define the primary operational properties of the working components, such as cutting ability, stability, and durability, and their appropriate selection ensures the technological reliability of cutting machines. The research presented in this article aims to investigate the dependence of a knife's cutting ability on a set of factors, including the type and conditions of the cutting process, the geometry of the knives, and the cutting force. The study involves an analytical examination of the cutting ability of knives during three main periods: running-in, steady-state, and blunting. Additionally, a block diagram is developed to optimize the parameters of the knife's microgeometry. The research methods employed include analytical investigations using engineering calculations.

Reliability Analysis of Electric Vehicle Charging Station Using Risk-Based Inspection Method and Reliability Block Diagram

Due to the increasing market demand for electric vehicles, particularly electric cars, the infrastructure for electric vehicles is also being fulfilled. This research utilized two methods: Risk Based Inspection and Reliability Block Diagram. Through the Risk Based Inspection method, a Risk Priority Number was obtained which identifies critical points in the Electric Vehicle Charging Station (EVCS). The Block Diagram method established relationships between interconnected subsystems. The research findings indicate that the critical point of the EVCS lies within the Body subsystem. This discovery significantly contributes to raising awareness about EVCS, ensuring that stakeholders entering the EVCS business have a clearer understanding and knowledge of the system.